1. Field of the Invention
This invention relates generally to the field of waterbeds and more specifically to a waterbed utilizing a pair of like fluid-filled mattresses and having improved surface continuity between the mattresses and reduced motion transfer and heat transfer between the mattresses.
2. Description of the Prior Art
Beds utilizing fluid-filled mattresses, commonly referred to as waterbeds, have become quite useful and popular items in recent years. Due to various problems which tend to detract from the comfort and convenience that might otherwise be enjoyed by the use of a waterbed by two occupants on a single fluid-filled mattress, dual mattress waterbeds were created. Examples of dual mattress waterbeds are shown in U.S. Pat. No. 3,732,585, issued to Krehbiel; and U.S. Pat. No. 3,736,604, issued to Carson, Jr.
One benefit of using dual mattresses is that the individual mattresses can be filled to the degree of surface softness or firmness preferred by each of the individual bed users. However, the use of dual mattresses in a waterbed has heretofore encountered major deterrents.
On a conventional fluid-filled mattress, when a person lies or sits at the edge of mattress, the edge of the mattress will collapse to a great extent under load, i.e. under the body weight of the person. When two water mattresses are placed side-by-side in abutting relation to form a dual water mattress bed, this collapsing phenomenon is amplified by the presence of two mattress edges causing an unacceptable "drop-off" at the location where the two mattresses abut each other. This "drop-off" tendency reduces the surface continuity of the waterbed to an unacceptable degree effectively eliminating the usefulness of the dual mattress configuration in the center portion of the surface of the waterbed. Heretofore, as a person lying on the waterbed moves towards the center portion of the bed where the mattresses abut, the "drop-off" effect causes the mattress edge to dip which accelerates the person's gravitation to the center portion of the bed. Thus the occupant or occupants of the bed tend to settle in the valley formed in the dual mattress configuration where the mattresses abut.
Another deterrent to the use of a conventional dual mattress waterbed is the transfer of wave motion caused by a person's movement on one mattress from that mattress to the abutting mattress. Any movement by the first person is directly felt by a second person lying on the bed due to this wave movement transfer. An attempt to alleviate this particular problem is set forth in U.S. Pat. No. 3,732,585, issued to Krehbiel, in which is disclosed a bed with a supporting frame having two adjacent compartments for supporting and containing two separate fluid-filled mattresses positioned in a side-by-side relation. The mattresses are partially separated by a rib extending upward from the bottom of the supporting frame. The upstanding rib, however, only partially separates the two mattresses from one another thereby allowing wave motion transfer where the two water mattresses are in contact with each other along the center of the bed. Furthermore, the upstanding rib is an unyielding protrusion which is noticed by an occupant of the bed when contacted.
Since many waterbeds are provided with thermostatically controlled electrical heating elements to maintain the mattress fluid at a sufficient temperature to insure mattress surface warmth and comfort, a third disadvantage of the conventional dual mattress waterbed configuration exists. Since the conventional system allows the two fluid-filled mattresses to lie in contact with each other along the center of the bed and since water is an excellent conductor of heat, the individual temperature of each of the mattresses cannot independently be controlled. Heat transfer will take place between the two mattresses where they contact each other. Even if each mattress has an independent heater system, the dual mattress system will eventually reach the higher temperature setting of either of the two mattress heaters due to this heat transfer.
While the prior art dual water mattress systems provide many benefits, there are no dual mattress waterbeds which create and maintain surface continuity between the mattresses to reduce the unacceptable "drop-off" phenomenon, nor are there any dual mattress waterbeds which provide both means for reducing wave motion and heat transfer between the two mattresses.
From the foregoing considerations, it should be apparent that there is a great need for an improved bed utilizing dual fluid-filled mattresses.
It is, thus, an object of the present invention to improve surface continuity in a bed utilizing dual fluid-filled mattresses.
Another object of the invention is to reduce the "drop-off" phenomenon at the center area of a bed utilizing dual fluid-filled mattresses.
A further object of the invention is to reduce motion transfer between the mattresses of a bed utilizing dual fluid-filled mattresses.
Still another object of the invention is to reduce heat transfer between the mattresses of a bed utilizing dual fluid-filled mattresses.
Yet another object of the present invention is to reduce motion transfer and heat transfer between the mattresses of a bed utilizing dual fluid-filled mattresses without interfering with the surface continuity between the mattresses and without otherwise interfering with the comfort of the bed occupant or occupants.
Other objects and features of the present invention will become apparent hereinafter with reference to the accompanying drawings and detailed description of the invention.